Field of the Invention
The present invention relates to a lithography apparatus that positions a substrate and forms a pattern on the substrate, and an article manufacturing method.
Description of the Related Art
In a semiconductor manufacturing process, lithography processing of forming a pattern on a wafer using a lithography apparatus such as an exposure apparatus is performed. In the lithography processing, process time shortening is required in addition to accuracy improvement. Hence, there is also a demand for shortening a measurement time needed for wafer alignment measurement.
Japanese Patent Laid-Open No. 2010-258009 describes performing readout based on the information of the size and starting point of an alignment mark region portion to shorten the measurement time by decreasing the transfer amount of data from an image sensor that has detected an alignment mark formed on a wafer.
In the technique of Japanese Patent Laid-Open No. 2010-258009, data processing is started without reading out the data of a portion after the alignment mark region portion in the image sensing region of the image sensor, thereby calculating the position of the alignment mark. This shortens the measurement time, as compared to a case where the data of the entire image sensing region is read out.
However, when measuring the position of an alignment mark, the substrate is normally positioned with respect to the image sensor such that the alignment mark is located at the center of the image sensing region. Hence, data not to be used to calculate the position of the alignment mark exists between the readout starting point of the entire image sensing region and the readout starting point of the alignment mark region portion.
In Japanese Patent Laid-Open No. 2010-258009, the data of the alignment mark region portion cannot be processed without reading out the data not to be used to calculate the position of the alignment mark and the data of the alignment mark region portion to be used for the calculation. As a result, measuring the position of the alignment mark takes time.